dict = {'help':'帮助','bike':'自行车','geek':'骇客','China':'中国'}
while True :
     word = input('请输入英文单词:')
     if word == ':end':
        break;
     value =dict.get(word)
     if value == None:
         print('{}在字典中不存在.'.format(word))
     else:
         print("{}的含义是{}".format(word,value))
         print(value )
